High Temperature printing

  • This is a two-in-one question on high temp printing. I consider nozzle-temperatures between 250°C and 480°C as "high".

    I have no real use for it at the moment, but I would like to be able to print high-temp materials. Therefore I would like to use my existing printers (Tevo Little Monster with Smart Effector, Anycubic Kossel with smart effector and mostly unmodified Sapphire Pro). As far as I understood I need an all-metal hotend with a copper heater block, copper-nozzle, full-metal heatbreak, pt1000 and heater cartridge with at least 50W . Further I need a build room enclosure and a strong heatbed.

    Is this correct? What else is needed or recommended? How hot may the build room become for the smart effector, the magnets, the belts? How much air temperature can the fans take? Is a air-cooled heatsink still suitable? What material is suitable for the enclosure? Is there something like a heater block insulation sock made of ceramic?

    So my first question is: What would be a good guess how far I can get with my existing printers? How to safely test the limits?

    Second: I am planning to build my own 3d-printer (someday). At the Moment it is not more than a rough idea and it might take years to become a working machine. Probably it will have a CoreXYU-geometry and direct extruders.
    But I wonder what are the designed-constraints to make high-temp printing possible? Is the 200°C-high-temp printbed from e3d sufficient for all printable materials? Does this mean 200°C Air Temp in the printing chamber?
    Are the usual GT2 tooth-belts (which are made of some kind of rubber) still suitable? What might be a good (ideally transparent) material for enclosure? Do linear rails work as expected at these temperatures? Are special lubricants needed? What print bed surface is suitable? What about the temperature resilience of the filament feeder tubes and print head wiring?

  • I’m going to jump and an follow this one.

    But I also have a printer that I have recently modified to print at the temps you are talking about. From the factory this print was able to print 300C at the hot end with a build chamber up to 70C and the heat bed up to 160C. It is a CoreXY machine and the belts are in the build chamber. From stock it had 25W heaters and air cooled hot end.

    The first modification I made was to the heater cartridge and replaced it with a 40W heater as it really struggled to get to 300C, and could not maintain 300 if the part cooling turned on at all.

    Eventually I replaced the board with a duet 3 and the hotend is now a Titan aqua with liquid cooling (upgraded from e3D’s crappy system). I’m also running the copper volcano blocks and I once had the silicone socks on them but they deteriorated quickly printing at 300C. The printer still runs at those temps fine but I had to retune the PiD.

    Keep in mind that as you get hotter print temps you also get plastics that are less tolerant of part cooling. So you don’t need the sock to insulate the hot end from the part cooler. I have on order some PEI to try printing. I want to try PEKK but at 1400$/kg that’s not happening any time soon.

  • @baird1fa said in High Temperature printing:

    It is a CoreXY machine and the belts are in the build chamber

    Are you aware of any printer design, where the belts are outside the build volume? How could that work without substantial holes in the enclosure?

    @baird1fa said in High Temperature printing:

    Keep in mind that as you get hotter print temps you also get plastics that are less tolerant of part cooling.

    So I can basically drop the material fans for materials that need high print temps?

  • @justus2342 I’m not aware of any design where the belts are out of the chamber. You would essentially need a hole the same size as the range of motion of the carriage, which is basically larger than the xy build volume. Moving the steppers out of the chamber is easy with a CoreXY design as you only need to holes to allow the belts to pass through. There are some pretty high temp belts out there.

    The build chamber doesn’t really need to be overly hot. I’ve see some that claim 200C but I’m not sure I see why. Any thermoplastics on the market don’t need a chamber that hot. 70-110 is the hottest I seen a call for in any filament.

    As for part cooling, yes you could eliminate the fan but it may not be a great idea. I’ve printed several parts in polycarbonate at 300C that still needed some part cooling. Usually only 10-30% fan speed and the “cooling” is being provided by 70C air. So it like cooling with a blow dryer. So if you do make a really hot build chamber you may need “cooling” to help solidify the part so it doesn’t just turn into a pile of goo.

  • Separation of the build volume and the motor/belt section can easily be done with bellows. I would suspect there would be issues with leakage or heat just traveling through the bellows but these things can be mitigated.
    No mater what, your costs for the printer increase exponentially as you allow for hotter and hotter build environments

  • I've acutally written my master's thesis about designing and building a HT printer. In my case, HT refers to a build chamber temperature of about 160-200 °C and nozzle temperatures of 350-450 °C.

    The main challenge was in fact to design a motion system that would either withstand the heat or be excluded from the heated and isolated build chamber. I chose igus drylin in a stainless version with HT capable gliding foils, as well as high pitch spindles with nuts from the same polymer (I work at igus and did my master's there, if someone wants to look at the design, do so here). In this case, the linear rails are kept in the build chamber while the spindles protrude through the isolation to the outside, where they are driven by the steppers.

    Doing so allowed me to bypass the Stratasys patent which seemed to be the sensible thing at the time.
    If I were to design one such printer again, I would change a few things over the last design (aside from general considerations like accessibility and manufacturability). Most notably I would consider changing to a belt-driven, maybe coreXY system that is isolated by bellows as suggested before. A design that incorporates this is shown here.

    In contrast to some who commented before, I'm very much of the opinion that the higher the chamber temperature, the better. While you can certainly produce some nice parts at 70 °C (at which temperature most available belts start to go out) sneaking up to Tg of the polymer is ideal and will allow to freely print parts of any shape without problems. And while for most use cases, materials like PA and PC (natural or filled) will do the trick, if you want to process materials like Ultem or PEEK (that have not been highly altered to be suited for lesser temperatures), you need that 160-200 °C chamber temperature at least.

    If it doesn't become clear from this, IMO it's not the main challenge to reach the required nozzle temps. A 60 W heater, maybe water cooling for the hotend and a berd-air system for part cooling (or pressurized air for both, which is available in most workshops) does the trick. In my setup I'm running an E3D setup with the standard heater cartridge. The standard temperature sensor cartridges are garbage in this application and have been replaced by a high quality, braided-line version.

  • i print 500C easily with a dyze hotend and extruder....works all day long

  • @imrj said in High Temperature printing:

    i print 500C easily with a dyze hotend and extruder....works all day long

    Could you share a little more detail on your printer, your overall setup, the material you use und the size of the objects you are printing?

  • Really interesting thread here.

    How about using lead screws for high temp chambers? It seems like you could adapt the Ultimaker style x/y mechanism to use lead screws instead of rods and belts, and thus keep everything sensitive outside the chamber. It could be made cheap and simple, except that you would probably need to make some custom metal parts.

  • @sonderzug I have a giant (1m cubed) custom high temp printer I've been building for years as I'm hoping to one day sell machines. I can confirm e3D's 60W premium heater in combination with the Chimera+ (Aqua), copper plated heater block and nozzle X will heat and hold heat beyond your wildest dreams. I only went up to 400C but the auto PID results said this configuration could reach >800 😄

  • @owlfab yeah, imo lead screws is the way to go (if you want to put all of the linear motion system into the heat chamber). Using high pitch (say 10 mm) screws gives you reasonable speeds while maintaining resolution.

    @Print3d thanks for the confirmation. Yeah I'm pretty sure it's just about the wattage of the heater. My problem is also that the Duet is thrown off when the enclosure is not as hot as it was during PID tuning.
    How do you solve heating the build volume? What temperatures can you reach?

  • wow, nice thread here guys!

  • Depending on the travel length and desired print speed lead screws or ball screws may suffer whip. Unless of course you compensate by increasing the diameter, which in turn increases weight & load on the drive motor to change direction. A balancing act for sure.

    One possible suggestion for passing belt drive through the sealed enclosure might be a thru axle. Please excuse my rough pic 😊


    You get the idea tho

  • @Hytek said in High Temperature printing:

    [...]lead screws or ball screws may suffer whip.

    I'm not sure to understand: do you mean there can be a mechanical issue? The screws can bend under load?

  • Yes, depending on the length, diameter & inertia force applied in the change of direction the lead screw can flex. In a slight case these 'flexes' will show up in the print surface. In heavier cases can cause unwanted noise, vibrations and shorten component life.
    I'm not saying lead screws can't be used, just suggesting there are things to consider when making that choice.

  • Ok, thanks!